This invention relates to document holders, and more particularly to binders for loose-leaf materials designed for binding and filing documents and other sheet-like materials in suspension filing systems.
Holders for loose-leaf materials, and in particular document holders designed to releasably bind such materials together and support the bound items in suspension filing systems are well known. For example, see U.S. Pat. No. 4,171,854 and the references cited therein. The document holder shown in U.S. Pat. No. 4,171,854 is basically in the form of a post binder, the spine of which is provided with integral hook means for mounting the holder to a suitable support hanger of a suspension filing system. Provision is made for securing the binder to either a top-loading two-rail suspension system or a side-loading single-rail suspension system. For the former type system, fixed support hooks are provided extending beyond the head- and tail-ends of the spine of the binder. For the latter type suspension system (the so-called "center rail" file), one or more hooks are recessed into the rear of the spine. As is typical with a post binder, the documents are secured to the binder by placing marginal apertures in the document over a series of posts or pins which project from one of the two halves of the binder and locking the other half of the binder to the first so as to captivate the posts.
It will be appreciated that the presence of fixed hooks projecting beyond the head- and tail-ends of the spine prevents a document bound in such a holder from being easily shelved as a conventional book. To overcome such problems, post binders incorporating retractable end hooks, such as disclosed in U.S. Pat. No. 3,801,175, are also known. In this last cited patent, the retractable end hooks are slidably mounted within the case of a post-style binder, and are held captive by the posts nearest the head- and tail-ends.
While such post-style binders are convenient for the storage of such stationary items as accounting summaries and the like, which may be added to seriatum, they are not convenient for the storage of loose-leaf documents which are subject to periodic extensive revision, in that intercalation is difficult. Loose-leaf notebooks incorporating a standard multi-ring mechanism overcome this problem, in that they readily permit the removal and insertion of pages within a document without requiring any other page to be removed.
Additionally, it should be noted that the two styles of suspension file require the filed document to be differently labeled for easy access. Thus, the two-rail suspension file is typically top loaded, with the spine of the post binder upermost, and accordingly is preferably labeled on the rear of the spine. On the other hand, the single-rail suspension file is typically side loaded, again with the spine of the bound item upermost, and is thus best labeled along the head edge of the document. In the prior art, such labels have typically been affixed to a portion of the spine. It will be appreciated that such a label extending from the spine along the head edge of the document would likely interfere with the operation of a retractable end hook recessed within the case. On the other hand, incorporating such a label into the retractable end hook would result in an awkward end hook.
It should also be noted that the retractable end hooks in some designs are not provided with means for securing them in the extended position. Such end hooks are subject to accidental retraction, as by hitting the end hook end-on against a rail of the suspension file system while filing the binder.
Finally, it will be appreciated that retractable hooks captivated by the posts of a post binder require the binding mechanism to be opened, with the possible loss of order of the bound document, in order to replace a broken hook.
Accordingly, it is an object of the present invention to provide a multi-ring binder adapted to be filed in a suspension filing system.
Yet another object of the invention is to provide a multi-ring binder with retractable end hooks, for use with double-rail suspension filing systems, and with recessed hook means for use with single-rail suspension filing systems.
Still another object of the invention is to provide a multi-ring binder with retractable end hooks and a head-end edge label.
A further object of the invention is to provided such a filing system with retractable end hooks which may be releasably secured in both closed and opened positions and which, although captivated to the binder, may be easily replaced without the need of removing documents from the binder.